Introduction: Primary hyperparathyroidism is the third most common endocrine disorder with an incidence of 3 per 1000 in Europe. An increased prevalence coexistent parathyroid and thyroid disease has been described. A combination of a huge goitre with a scan negative undescended retropharyngeal inferior parathyroid adenoma is presented, which is unusual and currently absent from published literature.
Case Report: A 71-year-old female with asymptomatic primary hyperparathyroidism and compressive symptoms from a very large toxic multinodular goitre is presented. Localization studies failed to identify a parathyroid adenoma. Computed tomography scan showed the left thyroid lobe to be larger with a significant retropharyngeal component, extrathoracic tracheal compromise and minor retrosternal extension. A combined total thyroidectomy and parathyroidectomy via a cervical approach was performed. During mobilization of the highly developed superior pole of the left thyroid lobe, a separate retropharyngeal structure was identified. This structure, measuring up to 63 mm, was recognized as a very large adenoma of what we interpret as a non-descended left inferior parathyroid gland. Histology showed a multinodular goitre with an incidentally found 0.2 mm papillary thyroid carcinoma and hyperplasia of all three parathyroid glands, including the very large (21 g) non-descended left inferior gland.
Conclusion: We believe this case to be unique in published literature given the huge goitre, unusual nature of the parathyroid disease and coincidentally found microcarcinoma. The primary value of this case lies in the illustration of the difficulties of parathyroid localization in the presence of a large goitre.